Electrical interlock



y 1953 A. G. ZIPPLER 2,639,007

ELECTRICAL INTERLOCK Filed Feb. 26, 1952 2 Sheets-Sheet 1 72 INVENTOR.

JrZkzor' Z iii/ iar BY ATTOR/Vf) May 19, 1953 A. G. ZIPPLER ELECTRICAL INTERLOCK 2 Sheets-Sheet 2 Filed Feb, 26, 1952 A TTOAWfY Patented May 19, 1953 UNITED STATES PATENT- OFFICE ELECTRICAL INTERLOGK Arthur i r hil del hia. Pa. Application February 26, 1952, Serial No; 273,507

7- Claims.

My invention relates to new and useful electrical interlocks such as are employed in connection with safetygates 'or doors. of elevator shaftsto control the operations of an, elevator and said safety gates or doors under certain predetermined relative conditions.

One of the objects of my invention is, to Pro:

vide an electrical interlock which may be, mount:

ed on either the right hand.- or left hand side of an elevator shaft. entrance, assuming that a person is inside of the shaft and face the entrance, without the. necessity of changing or rearranging the interior mechanism.

Another object of this. inventionis, to generally improve the construction of" electrical interlocks whichwill simplify the structural. and operational features and adapt them for use of either vertical side ofelevator shaft entrances.

A further object of th presentinyention is to produce. an electrical: interlock including'a box 'bodyprovided with. attaching wings and having vertical knifereceiving slots, one at each side of the device, said slots being open towards the outer sides and: at the tops for the purpose of guiding "a gate knife into operational relation with a'switchoperating lever and a locking-lever,

located: at one side of the device corresponding 'to the path of travel of the. knife or associated with, the respective slotpositioned; to receive said knife,;said locking lever being-maintained in a normally locked condition by a spring actuated shaft carrying a lock operating lever cooperating with an elevator car-cam to move. the locking lever to an unlocked position, and switch means withinthe box body for opening and. closing a circuit according-to the position of the car relative to a landing to control the car operating circuit.

With the above and. other objects in view this invention consists of the details of construction andicombinationcf elements hereinafter set forth and, then designated by the claims.

In; order that thoseski-lled in the art to which.

this invention appertains may understand how to make-and use the same I- will describeits construction in detail referring by numerals to the Fig. 3 is an enlarged side; view of the electrical interlock showing the'positions of the operating elements, including-a portion of the gate knife, when the safety gate is closed and the elevator nisaway fr the a d ns- Fig; .4 is a similar view with. the operating elements in the positions assumed when the car is at a landingand theassociated gate-isstill closed.

Fig; 5; also is a similar.- view with the car ata landing and its respective gate open.

Fig 6; is a further enlargedface, view of the electrical interlock with the cover and-cam roller moved F s. i ztifi al ectiona ew h reof o the line. l -lot 6 illustrating the switch m n c o e Fig; 8 is a similar view showing the switch means, open; a portion of the operating lever for h eak n e h in wk 0 T- 9- an upper end- View thereof.

Incarry-ingout invention as herein emrepresentsthe. electrical interlock which edon: a suitable support .I I, such as a gate pcst forming apart of the frame providing an entrance to an elevator shaft or well. .BY reference to Figs, 1 and q2, it will be apparent that theinterlockcan be. mounted at either the left hand, orright hand side of the. entrance which is; normally .closed; -by-a. gate. l2, or equivalent, vertically slidably. mounted in ,track' railsl3, and carrying a knife [.4 .cooperating'with the interlock-.- Also, cocperatingjwith the interlock is a cam 15 carried bythe, elevator car It represented by. the platform or bottom thereof which, under. certain. conditions. is to be stopped at a landing I] from which the. entrance provides a communicationwith the elevator shaft or well and the car v whenthe latter is approximately level. with said. landing. It should be obvious that .a plurality. of; entrances to the elevator shaft can be provided, one above. another at different landings, at opposite sides. of the. shaft at the same landing or any. otherdesirable. and suitable locations although only .one, is. shown :and'described herein for purposes. of explanation of the inv i n- The mterlock l-llcom liises a box body H3, includingthe.usual sides, upper. and. lower end wallsand back-while-the front is open but norvmally closed. by. a lid l9. detachably held. in place by, suitable fastening devices, such as screws, and the upper and lowerwingsiflandl l, respectively, having holes to-receive screws or-other equivalent attaching means; for. mounting the apparatus on a sup o r wail q bhebQfiY hen side hereq from the upper end wall to a location adjacent but spaced from the lower end wall is thickened slightly to provide areas of sufficient size to permit the formation of the opposed vertical side slots 22 and 23 open at the top and opposite sides of the apparatus to the exterior thereof. One of these slots is adapted to receiv the free end of the gate knife 14 depending upon which side of the entrance or gate the interlock is mounted for operation.

The face of the upper wing at the upper edge thereof is beveled at 24 and 25 directly above the slots and the back of the body is likewise beveled at 26 and 21 at the upper ends of said slots to provide flared mouths or guideways for the slots to insure unobstructed entrance of the knife into either slot should said knife become misaligned, accidentally or through poor fitting of associated parts.

The thickened portions of the back Wall may be so fashioned as to produce vertical longitudinal projections 28, Fig. 6, on theinterior of the box body, one projection at each side of the body and spaced apart to provide a channel 29 in which a block of insulation material 30 may be mounted.

On the insulation block 30 is a binding post 3| to which is secured a conductor 32, Figs. 1 to 5, projecting through a hole 33, Figs. 7, 8 and 9, in the top end wall of the box body and said hole may be suitably fashioned to receive a connector 34. The binding post 3| is electrically connected to a contact post 35, as by a bonding strip 36.

Another bonding post 31 is also mounted on the insulation block 30 adjacent the lower end of the latter and a conductor 38 which projects through a hole 39 in the bottom end wall of the box body is attached to said binding post 31 and like the hole in the top end wall, the hole 39 may be appropriately fashioned to receive a connector 40. The binding post 31 is also electrically connected with the movable contactor 4|, of the switch or circuit maker and breaker 42, by a pigtail or flexible conductor 43.

The switch 42 includes, in addition to the stationary contact post and movable contactor 4|, a panel 44' of insulation material to which said movable contactor is resiliently attached by the pegs 45, coil springs 46, washers 41 and cotter pins 48 in a well known or conventional manner. Said switch, especially the insulation panel thereof, is fixed to the contact shaft 49 that is journalled in the side walls of the box body with the ends of said shaft protruding beyond the outer faces of said body side walls. For the purpose of properly positioning the switch, the contact shaft 49 may have a flat 51! intermediate its ends so as to be located substantially midway between the side walls within the body compartment and the panel 44 engages the flat and is fastened in place by securing means 5|, such as screws. The contact shaft 49 is urged in a rotational direction, which will normally maintain the movable contactor 4| out of engagement with the contact post 35, by a spring 52, Fig. 6, such as one of the coil type surrounding said shaft with one end attached to the shaft and the other end resting against the interior of the body back wall.

On one protruding end of the contact shaft is detachably mounted a holding means 53, such as a collar, to assist in preventing accidental displacement of said contact shaft but permitting removal of said shaft when desired. On the other protruding end of the same contact shaft 49 is also detachably mounted a contact lever 54 having a flat or square heel 55 at its lower end for coaction, under certain conditions, with the: flat or square stop surface 55 on the upper por-- tion of each of the external lugs 51 and 58, one on each side of the box body or on opposite side: walls of said body. Said contact lever is so weighted that the switch will open even if thespring 52 accidentally breaks. In addition said contact lever 54 has a toe 59 projecting from the lower portion thereof towards the back of the device and across one of the slots 22, 23. At the upper end of the contact lever 54 is a nose 63 having beveled or canted upper and lower surfaces, Fig. 4, whereby said contact lever, when lying across a slot 22, 23, may be retracted by the knife I4 moving in either direction, it being. understood that said contact lever 54 extends upwardly in a generally vertical direction, the same as the switch contactor 4 I, from the contact shaft- 49.

A look shaft Bl journalled in the side walls of the body with the ends of said shaft protruding beyond the exterior surfaces of said side wall and, more particularly, the lugs 51, 58 which, by preference, are thicker than or approximately the same thickness as the contact lever 54. The lock shaft may be held against endwise or longitudinal movements by washers 62 and cotter pins as on the shaft inside of the body to prevent accidental displacement of said lock shaft, although it can be dismounted.

On one protruding end the lock shaft 6 l which is below the plane of the bottoms of the slots 22, 23, is detachably mounted a locking lever 64 that extends upwardly along side of the contact lever 54, but free therefrom, and this locking lever has a nose to project across the vertical plane of either of said slots 22, 23. The nose of said locking lever has a beveled or canted upper edge 65 and undercut primary and secondary or safety locking surfaces, 66, 61, respectively, the latter extending beyond the former and in a different or higher plane. The primary locking surface 65 is adapted to engage the upper edge of the knife when the latter is in one of the slots 22, 23, with which the locking lever is associated, while the car is away from the landing, but if for some unexpected reason, such as the knife not fully entering the slot, the secondary locking surface 61 will engage the knife and prevent opening of the gate.

The lock shaft BI is urged in a rotational direction which will normally project the nose of the locking lever 64 across the plane of the slots 22, 23 by a spring 6B,preferably of the coiled type, surrounding said lock shaft with one end of the spring fastened to the lock shaft and the other end engaging the inner surface of the back of the body, for example. Also the locking lever 64 is so weighted that it will move to the holding position even if the spring 38 accidentally breaks.

On an end of the lock shaft 6|, generally the protruding end opposite that on which the locking lever 64' is mounted, although it can be otherwise, is detachably mounted the pendant operating lever 69 for cooperation with the cam I5 on the car I6 and, by preference, a cam roller 10 is mounted on the lower free end of said operating lever to actually engage the cam with a minimum of friction. The cam l5, which is mounted on the car l6, has a straight vertical portion H to hold the locking lever in a retracted position, against the action of the spring 68, and outturned upper and lower end guide portions I2.

In practice, the electrical interlock is installed aeeewov oneitherthe-right hand or left-hand side of one or each entrance to the elevator shaft, generally being I mounted on the frame" in- =whicha gate is vertically 'slid'abl'y mounted and the electrical connections are made with a sourceof'power and a contact which makes and breaks the elevator operating power. The electrical'currentwhich operates the-elevator does-not pass through any interlock and where therei's a plurality of interlocks, such as-those at a-number of" different land'- ings, said interlocks are wired in'ser-ies' thus when the circuit is broken at one-interlock it is, in

efiechbroken at all interlock locations.

When the interlockis looated'on-the left hand side of the entrance, Figpl, the knife [4 is attached tothe left hand side of the safety gate [2' and said knife and "associated relatively positioned-whereby the knife may enter the right hand side slot 23 in the interlock as the gate is moved-to the closed position andwithdrawn from saidslot when the gate is opened. Under suchconditions the locking lever and the contact lever are mounted'on the right hand ends of their respective shafts and the operating lever 69 is properly mounted on thelock shaft to be essary but in most instances the contact lever and collar are merely interchanged and usually the locking lever and'operating lever'are likewise interchanged. In' the latter instance though it is possible that the operating lever can be onthe same end of thelock shaft as the looking lever. This reversal of the contact andlocking lev'erswillplace them in association with the left hand side slot 22 and position for cooperation with the knife mounted on the right hand side of the. safety gate for movement into and out of said left hand "side slot.

Adapting the device for installation on either side of the entrance requires no changes in or substitution of differently styled parts of the apparatus but merely the proper mounting of the contact and locking levers on the appropriate ends of their respective shafts while the elements inside of the box body remain undisturbed. Of course, it must be ascertained that when both the contact and locking levers are retracted, the

contactor M is also retracted and the operating lever 69 is in a projected position or close to the back wall of the apparatus.

In either instance, when the safety gate is closed the knife It will be in one of the slots 22, 23, according to which side of the entrance the interlock is mounted on, for example that depicted in Fig. 3. Assuming that there is no car at the landing, then the spring '88 will urge the lock shaft iii in a rotational direction to hold the nose of the locking lever 54 across the knife and retain the safety gate in a closed position. At the same time said knife will be in engagement with the toe 59 of the contact lever 54 and hold it in the projected position which maintains the switch 42 closed, Fig. 7, so that the elevator is free to be operated. While the switch is closed, even if the knife is raised slightly, the spring '52 on the contact shaft 49 i not strong enough to overcome the weight of associated part st and: retract the contactleyen and open the switch. I

When a car.approaches and-reacheswaglanding,

Fig. 4-, the cam; l5.- engages; the: operatinglever .69; particularly: the 'roller- 10; a-Ildprojects, said 4'2; Fig. 8; andspreventoperation of the elevator car whileit isxat :the landing.

Whenthe gate: is again lowered; the-knife will enterl the slot'with whichsaid knife'is associated, asslot' '22',Fig e, and. engage the toe "of the contact lever-to 'proj ecta the "nose thereof. across the" vertical plane of the: slot and close the switch e2-,--Fig'. "7, after'which the car maybe operated. As the ear -moves awayfrom the. landing the cam l5 will'be-carried'out of engagement with the operating lever '59 'releasingthe spring actuated-lock shaft-s0 that the 'noseof'the l ocking lever can be-projeeted'across the-plane of said slot, as-22', above the kni-fe-toheld the latter and thereby prevent opening of the safety gate while the car'is away from the landing. During the time the car is between landingsor floors at different levels noneof the safety gates can be opened and the interlock electrical circuit cannot be broken or opened wherefore the elevator can be operated at will;

If, through some unforeseen reason, the knife is out-of its slot and the noses of either or both the contact and locl zing'levers are in a positionacross the plane of the slot; the gatecan be closed because as said gate is moved towards the closed position the knife will engage the beveled upper edges of the noses of either or both of the contact and locking levers and temporarily retract them. As soonas the knife has pa-ssed beyond saidnoses they are in condition to be again projected across the plane of the slot.-

From the foregoing it will be apparent that I have produced a relatively simple, compact and inexpensive electrical interlock which is strong and durable and capable of long usage with very little chance of getting out of proper working condition due to wear and tear.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the appended claims without departing from the spirit of my invention.

Having described my invention, what I claim as new and useful is:

1. .An electrical interlock comprising a box body including back, side and upper and lower end walls providing a compartment with an open front normally closed by a detachable cover, said back wall having vertical slots therein at opposite sides thereof and open at the top and the respective opposite outer sides of the body, said interlock adapted to be mounted on either side of an elevator well entrance whereby one of said slots is adjacent to and facing towards said entrance, such slot adapted to receive a knife carried by a safety gate vertically slidably mounted in said entrance, a lock shaft projecting through the body and journalled in the side walls with the ends of said lock shaft protruding beyond the side walls, a locking lever detachably mounted on the end of the lock shaft at the same side of the body as the slot with which the knife cooperates, said locking lever having a nose for projection across the vertical plane of the slot to hold the knife therein, means to normally urge the locking lever in a direction to cause its nose to project across the vertical plane of the slot, an operating lever detachably fastened to said lock shaft to be acted upon by means carried by an elevator car to retract the locking lever, a contact shaft projecting through the body and journalled in the side walls with the ends of said contact shaft protruding beyond the side walls, a contact lever detachably mounted on an end of said lock shaft at the same side of the body as the slot with which the knife cooperates, said contact lever having a nose with upper and lower beveled edges and adapted to be projected across the vertical plane of the slot, means as a part of said contact lever to be acted upon by the knife for projecting the contact lever nose across said vertical plane of the slot, said contact lever nose to be retracted by direct action of the knife thereon, an electrical switch within the body compartment and including a contactor on the contact shaft, and a light tensioned spring to normally urge said contact shaft in a rotational direction to maintain the switch opened.

2. The electrical interlock according to claim 1 wherein the upper edge of the nose of the looking lever is beveled.

3. The electrical interlock according to claim 1 wherein the lower edge of the nose of the locking lever is undercut on two different levels.

4. The electrical interlock according to claim 1 wherein the upper edge of the nose of the looking lever is beveled and .the lower edge of said nose is undercut on two different levels.

5. The electrical interlock according to claim 1 wherein the front and rear walls of each slot at its upper end are beveled outwardly to provide a flared mouth to each slot.

6. The electrical interlock according to claim 1 wherein the means as a part of the contact lever to be acted upon by the knife is a toe projecting across the vertical plane of the slot adjacent the lower end thereof and wherein said contact lever has a square heel to the rear thereof, in combination with a lug on either side of the body having a flat upper stop surface to be engaged by the heel of the contact lever as the latter is retracted.

7. An electrical interlock comprising a box body including back, side and upper and lower end walls forming a compartment with an open front closed by a detachable cover, said back wall having vertical slots therein at opposite sides thereof and open at the tops and the respective opposite outer sides of the body, a contact shaft projecting through the body and journalled in the body side walls with the ends of said contact shaft protruding beyond said body sides, a contact lever selectively and detachably mounted on either end of said contact shaft, said contact lever having a nose at the outer end thereof for projection across and retraction from the vertical plane of the slot on the same side of the body as the assembled contact lever and adjacent the upper end of said slot, a toe on the lower part of the contact lever constantly projecting across the vertical plane of the slot adjacent the lower end thereof, a switch within the body including a movable element connected with the contact shaft, means to maintain said switch open when opened, the same being closed and opened by actuation of the contact lever, a lock shaft projecting through the body and journalled in the side walls with the end of said lock shaft protruding beyond said body sides, a locking lever selectively and detachably mounted on either end of said lock shaft and beside the contact lever, said locking lever having a nose for projection across the vertical plane of the same slot as the nose of the locking lever and retraction therefrom, means to normally urge said locking lever in a projected direction, and means on the lock shaft whereby said locking lever may be retracted when said last mentioned means is actuated in opposition to the locking lever projecting means.

ARTHUR G. ZIPPLER.

No references cited. 

